This invention relates to polyfunctional polyolefins and more specifically to polyfunctional polybutene polymers. The invention is also directed to methods of introducing the proper level of functionality in polybutylene materials. The invention is further directed to polycarboxylic functionalized polyolefins and methods of making which include preforming of an adduct that contains at least three or more functional carboxylic acid groups which can then be grafted via a free radical initiated reaction to active sites in polyolefins such as polybutylene and polypropylene polymers.
The instant invention also provides a method for improving the polarity of polybutylene by grafting a small molecule, which contains several acid functional groups to the hydrocarbon backbone of polybutylene. The increased functionality offers an abundant potential for various choices of chemistry in polymer modification.
The present invention also relates to a process for producing a graft modified polyolefin having good adhesion to polar materials such as nylon, polyester, glass, metal, etc.
The invention further relates to a superior functionalized polybutylene which is suitable for several new applications such as for hot melt adhesives and for emulsions. Applicants have discovered a new method which results in the grafting of small molecules of bi-functional N-substituted diacids to an unsaturated carboxylic acid, such as maleic anhydride, which can be grafted to polybutylene. The small chelate, iminodiacetic acid (IDA), is very effective because it is very reactive and can coordinate with most metals to form stable structures. The increased functionality of the grafted polymer provides higher adhesive strength in adhesive joints in a number of different substrates.
Because of the unique set of properties of polyolefins such as polybutylene and polypropylene, particularly their high compliance compared to other polyolefins and their comparatively low melting temperature, a functionalized version becomes an excellent candidate to fill the requirements of a structural hot melt adhesive. Polybutylene without functional groups lacks the functionality or polarity needed for the adhesion to high surface energy substrates, a necessary characteristic for both hot melt adhesives and their constituents.
Polybutylene, like other polyolefins, has no functionality on the chain and therefore artifacts made from this polymer have very low surface free energy and can not be decorated by painting or printing. In the past, researchers have reacted functional groups on the surface of polyolefins by various means using highly oxidative techniques to induce bonding sites with reagents leaving hydroxyl or carboxyl groups. Also, melt reactions have been carried out to functionalize the bulk of the polyolefin material by a free radical initiated reaction induced by organic peroxides.
A large number of polymer companies commercially offer functionalized polyolefin materials such as acrylated and maleated polypropylene and polyethylene. Techniques used to modify these polymers provide one or, at most, two acid groups per grafting site. The present inventor has found that by increasing the number of functional groups to three or greater per grafting site one can substantially improve the polarity and hence improve the polymer""s performance in several end use application.
Additionally, there is an ever increasing impetus to replace or supplement solvent-based polymer coating compositions with aqueous-based counterparts due to the environmental toxicity and flammability problems posed by the use of volatile organic solvents. However, even where aqueous-based polymer compositions have been devised, their production has usually entailed the intermediate use of organic solvents, requiring subsequent removal which is costly and time-consuming, or the incorporation of a certain amount of a solvent in the final composition which acts to ensure proper film-formation on coating (known as a coalescing solvent). There is therefore also now increasing pressure to significantly reduce or eliminate the volatile organic contents (VOCS) in aqueous-based polymer composition syntheses both as components in their production (even if subsequently removed) and in the resulting composition as an aid to film coalescence.
In the present invention, applicants have found unexpectedly that multi-carboxylic acid as the functional group can co-ordinate very effectively with most metals to form stable, e.g. octahedral, anionic complexes. For example, two moles of iminodiacetic acid contain four carboxylic acid groups, which can react with metal ions to form to have stability constant in excess of 1010. The introduction of carboxylic functionality into polyolefins allow for more water solubility as well as production of water borne products which are environmentally desirable.
The present invention is directed to a grafted polyolefin comprising the reaction product of: (a) a polyolefin which had been grafted with an unsaturated carboxylic acid anhydride or acid thereof; and (b) an amino carboxylic acid.
The instant invention is also directed to a grafted polyolefin comprising the reaction product of: (a) a polyolefin; and (b) an amino carboxylic acid.
The invention further relates to a grafted polyolefin comprising the reaction product of: (a) a polyolefin; (b) an unsaturated carboxylic acid anhydride or unsaturated carboxylic acid; and (c) an amino carboxylic acid.
The invention also describes a grafted polybutylene polymer comprising the free radical grafting reaction product of polybutylene and iminodiacetic acid.
In a further aspect of the invention, there is described a grafted polybutylene polymer comprising the free radical grafting reaction product of polybutylene and maleic anhydride further reacted with iminodiacetic acid.
The invention also provides ( 1) a compound (adduct), made by reacting maleic acid anhydride ( ester ) with iminodiacetic acid or a salt thereof and useful for grafting polyolefins, which compound has a formula selected from the group consisting of formula [1], [2], [3] below and mixtures thereof; (2) a process for making multi-functional polyolefins by grafting polyolefin such as polypropylene or polybutylene with such compound; and (3) a multifunctionalized polyolefin made by such process. The compound (adduct) formula selected from the group consisting of formula [1], [2], [3] below and mixtures thereof: 
wherein M+is Na+, K+, Li+, or Cs+
The compound (monomer) can also further react to form dimer, trimer and oligomer.
The invention further provides a grafted polybutylene homopolymer or copolymer having 1-50, preferably 1-30, more preferably 2-15 mole percent of an alpha olefin having from 2-8 carbon atoms, wherein the polybutylene is grafted with from about 0.01 to about 30, preferably from about 1 to about 15, more preferably from about 3 to about 10 weight percent of iminodiacetic acid
The present invention also provides an adhesive composition comprising the multi-functional polyolefins, particularly multi-functional poly-1-butene, described above. Particularly, the present invention also provides an adhesive composition comprising the reaction product of (a) a polybutylene compound consisting of polybutylene modified by grafting thereto an unsaturated monomer bearing an acid, ester or acid anhydride group, with (b) an amino polycarboxylic acid compound or a salt thereof bearing at least one primary or secondary amine groups, which are reactive with the anhydride group.
The invention is also directed to an emulsion composition comprising: (1) 25 to 55 weight percent of a grafted polyolefin comprising the reaction product of (i) a polyolefin, (ii) an ethylenically unsaturated monomer having functionality capable of reacting with an amino group and (iii) an amino carboxylic acid or a salt thereof; (2) a minor amount up to 10 weight percent of a surfactant; and (3) 55 to 80 weight percent water.
While the present invention is described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
The preferred mode of grafting the polyolefins is via free-radical grafting using peroxide initiators although other initiators such as azo compounds can be used. The organic peroxides which may be suitably used in the present invention are those having a decomposition temperature of preferably from 80xc2x0 C. to 230xc2x0 C., preferably from 110xc2x0 C. to 220xc2x0 C. and more preferably from 110C. to 210xc2x0 C.
Particularly preferred organic peroxide compounds have half lives at 210xc2x0 C. of from 1 to 30 seconds. Among these compounds, dicumyl peroxide, monocumyl tert-butyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di-(tert-butylperoxy)-hexane and 2,5-dimethyl-2,5-di-(tert-butylperoxy)-hex-3-yne are particularly noteworthy. Other peroxides which can be used in the practice of the present invention include benzoylperoxide, acetylperoxide, di-t-butylperoxide, t-butylperoxylaurate, dicumylperoxide, 1,3-bis(t-butylperoxyisoprypyl)benzene, 1-4-bis(t-butylperoxypropyl)benzene, 2,5-di-(t-butylperoxy)hexane, t-butylperoxybenzoate, -butyl4,4-bis-(t-butylperoxy)-valerate, octanoylperoxide, p-methane hydroperoxide, and t-butylperoxyacetate; azobis-compounds such as azobisisobutylnitrile, 2,2-azobis(2,4,4-trismethyvaleronitrile), and 2,2-azobis(2-cyclopropylpropionitrile); inorganic peroxides such as potassium persulfate, sodium persulfate, and ammonium persulfate may be recited.
The free radical-generator is generally used in the process according to the invention in a sufficient quantity to make it possible to effect the grafting. Furthermore, it is desirable that the quantity should not exceed the minimum quantity needed because any excess of radical-generator results in a degradation of the polyolefin. The quantity is usually at least 0.005 parts by weight per 100 parts by weight of polyolefin; it is in particular at least 0.01 part by weight, values of at least 0.02 parts by weight being the most advantageous ones. In general the quantity does not exceed 1 part by weight per 100 parts by weight of polyolefin, preferably 0.5 parts by weight, values of not more than 0.1 being the most recommended ones, for example approximately 0.04 parts by weight.
The peroxide under proper temperature homolytically decomposes, generates a free radical which abstracts hydrogen from the tertiary carbon of the polyolefin polymer, thus providing a reaction site for vinyl monomers or other labile molecules. The reaction is characterized as a random free radical event reaction without any bias toward distribution along the polymer chain.
The polyolefin homopolymers or copolymers are modified by grafting with a radically polymerizable unsaturated grafting compound selected from the group consisting of vinyl-polymerizable, unsaturated, hydrolyzable silane compounds, carboxylic acids and derivatives, carboxylic acid anhydrides and derivatives, and mixtures thereof, in the presence of a free radical generator. In the present invention, the ethylenically unsaturated grafting monomer typically contains a functional group capable of reacting with an amino functional group.
The vinyl-polymerizable unsaturated, hydrolyzable silanes used in this invention contain at least one silicon-bonded hydrolyzable group, such as, for example, alkoxy, halogen, and acryloxy, and at least one silicon-bonded vinyl-polymerizable unsaturated group such as, for example, vinyl, gamma-methacryloxypropyl, alkenyl gamma-acryloxpropyl, 6-acryloxyhexyltriethoxysilane, alkyloxypropyl, ethynyl, and 2-propynyl and preferably is an ethylenically unsaturated group. Any remaining valances of silicon not satisfied by a hydrolyzable group or a vinyl-polymerizable unsaturated group being satisfied by a monovalent hydrocarbon group, such as, for example, methyl, ethyl, propyl, isopropyl, butyl, pentyl, isobutyl, isopentyl, octyl, decyl, cyclohexyl, cyclopentyl, benzyl, phenyl, phenylethyl, and naphthyl. Suitable silanes of this type include those represented by the formula:
RaSiXbYc
wherein R is a monovalent hydrocarbon group, X is a silicon-bonded hydrolyzable group, Y is a silicon-bonded monovalent organic group containing at least one vinylpolymerizable unsaturated bond, a is an integer of 0 to 2, preferably 0; b is an integer of 1 to 3, preferably 3; c is an integer of 1 to 3, preferably 1; and a+b+c is equal to 4.
Suitable vinyl polymerizable unsaturated hydrolyzable silanes that can be used in this invention include, but are not limited to, 3-acryloxypropyltriethoxysilane, ethynyltriethoxysilane, 2-propynyltrichlorosilane, 3-acryloxypropyidimethylchlorosilane, 3-acryloxypropyidimethylmethoxysilane, 3-acryloxypropylmethyldichlorosilane, 3-acryloxypropyltrichlorosilane, 3-acryloxypropyltrimethoxysilane, allyldimethylchlorosilane, allylmethyldichlorosilane, allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, chloromethyidimethylvinylsilane, [2-(3-cyclohexenyl)ehtyl]dimethylchlorosilane, 2-(3-cyclohexenyl)ethyltrimethoxysilane, 3-cyclohexenyltrichlorosilane, diphenylvinylchlorosilane, diphenylvinylethoxysilane, (5-hexenyl)dimethylchlorosilane, (5-hexenyl)dimethylchlorosilane, 5-hexenyltrichlorosilane, methacryloxpropyldimethylchlorosilane, 3-methacryloxypropyidimethylethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltrichlorosilane, methyl-2-(3-cyclohexenyl)ethyldichlorosilane, methyl-3-(trimethylsiloxy)crotonate, 7-octenyltrichlorosilane, 7-octenyltrimethoxysilane, 1-phenyl-1-trimethylsiloxyethylene, phenylvinyldichlorosilane, styrylethyltrimethoxysilane, 13-tetradecenyltrichlorosilane, 4-[2-(trichlorosilyl)ethyl]cyclohexene, 2-(trimethylsiloxy)ethylmethacrylate, 3-(trimethylsilyl)cyclopentene, vinyldimethylchlorosilane, vinyldimethylethoxysilane, vinylethyldichlorosilane, vinylmethyldiacetoxysilane, vinylmethyldichlorosilane, vinylmethyldiethoxysilane, vinyltrimethylsilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris(beta-methoxyethoxy)silane, vinyltriacetoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-methacryloxypropyltris(beta-methoxyethoxy)silane.
The preferred silane compounds are vinyltrichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris(beta-methoxyethoxy)silane, vinyltriacetoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyltris(beta-methoxyethoxy)silane, and mixtures thereof. These compounds are preferred due to commercial availability, ease of use, as well as good polymer property improvement.
The radically polymerizable unsaturated grafting compound also can be a carboxylic acid or an anhydride thereof, with about three to about 10 carbon atoms, with preferably at least one olefinic unsaturation, and derivatives thereof. Examples of the carboxylic acid and anhydride include, but are not limited to, an unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid; an unsaturated dicarboxylic acid such as maleic acid, fumaric acid, itaconic acid, citraconic acid, allyl succinic acid, mesaconic acid, glutaconic acid, Nadic acid (norbornene-2,3-dicarboxylic acid), methyl Nadic acid, tetrahydrophthalic acid, or methylhexahydrphthalic acid; an unsaturated dicarboxylic anhydride such as maleic anhydride, itaconic anhydride, citraconic anhydride, allyl succinic anhydride, glutaconic anhydride, Nadic anhydride (norbornene-2,3-dicarboxylic anhydride), methyl Nadic anhydride, tetrahydrophthalic anhydride, or methyltetrahydrophthalic anhydride; or a mixture of 2 or more thereof. Of these unsaturated carboyxlic acids and acid anhydrides thereof, maleic acid, maleic anhydride, Nadic acid, methyl Nadic acid, methyl Nadic anhydride, or Nadic anhydride is preferably used. The most preferred anhydride is maleic anhydride.
The quantity of graftable functional monomer used in the process according to the invention depends on the properties which it is intended to obtain in the grafted polyolefin, the quantity of radical-generator used and the residence time of the mixture in the reactor. It is generally sufficient to permit an improvement in the properties of the grafted polyolefin obtained. In practice there is no interest in using an excessive quantity because any excess beyond the quantity needed to obtain the maximum degree of grafting does not bring about any improvement in the finished product. The quantity is usually at least 0.01 part to 20 parts by weight per 100 parts by weight of polyolefin; it is preferably at least 0.1 part to 17 parts by weight; and most preferably 1 part to 15 parts by weight per 100 parts of polyolefin. Values of at least 10 parts by weight are the most commonplace. In general the quantity does not exceed 20 parts by weight per 100 parts by weight of polyolefin; in most cases it does not exceed 17 parts by weight, with values not exceeding 15 parts by weight being those most recommended.
The other reactive component used in the practice of the present invention is an amino carboxylic acid and more preferably an amino polycarboxylic acid. Typically, the amino carboxylic acid has the formula HNR2 or H2NR wherein R is a carboxy functionalized aliphatic group containing 1-8 carbon atoms. The R group can also be a carboxy functionalized aromatic group such as aryl or naphthyl. Illustrative non-limiting examples of the amino carboxylic acids include glycine, glycylglycine, alanine, valine, leucine, isoleucine, phenylalanine, tyrosine, proline, hydroxyproline, serine, threonine, 3-amino-3-methylbutanoic acid, 6-aminocaproic acid, aminobenzoic acid (meta and para), 4-aminosalicylic acid, iminodiacetic acid, lanthionine, methionine, aspartic acid, glutamic acid, lysine, delta-aminolevulinic acid, beta-alanine, alpha-aminobutyric acid, gamma-aminobutyric acid, gamma, epsilon-diaminopimelic acid, gamma, alpha-diaminobutyric acid, ornithine, omega-aminododecanoic acid, beta-cyanoalanine, epsilon-methylhistidine, canavanine, djenkoic acid, 1-azaserine, gamma-methylene glutamic acid, N-methyl tyrosine, arginine, tryptophan, norvaline, cystine, cysteine, imidazole-4,5-dicarboxylic acid and hydroxylysine. The preferred amino carboxylic acid is an amino polycarboxylic acid with iminodiacetic acid being the most preferred. Other amino polycarboxylic acids that can be used are selected from the group consisting of beta-alanine diacetic acid, ethylene diamine triacetic acid, diethylene triamine pentaacetic acid, trans-1,2-diamino cyclohexane triacetic acid.
The amount of the amino carboxylic acid or a salt thereof that is used in the present invention depends on the level of final functionality that is desired for a given industrial application. In the case where the polyolefin is first grafted with a the reactive unsaturated monomer, the amount used is at least sufficient to functionalize 50% of the reactive groups. For example, in the case of a maleic anhydride grafted polyolefin, at least one mole of amino carboxylic acid per grafted anhydride moiety is used. Of course, the full stoichiometric amount of amino polycarboxylic acid can be used to fully react all of the grafted anhydride moieties.
When the amino carboxylic acid or its salt is grafted directly, the quantity of graftable material used in the process according to the invention depends on the properties which it is intended to obtain in the grafted polyolefin, the quantity of radical-generator used and the residence time of the mixture in the reactor. It is generally sufficient to permit an improvement in the properties of the grafted polyolefin obtained. In practice there is no interest in using an excessive quantity because any excess beyond the quantity needed to obtain the maximum degree of grafting does not bring about any improvement in the finished product. The quantity is usually at least 0.01 part to 20 parts by weight per 100 parts by weight of polyolefin; it is preferably at least 0.1 part to 17 parts by weight; and most preferably 1 part to 15 parts by weight per 100 parts of polyolefin. Values of at least 10 parts by weight are the most commonplace. In general the quantity does not exceed 20 parts by weight per 100 parts by weight of polyolefin; in most cases it does not exceed 17 parts by weight, with values not exceeding 15 parts by weight being those most recommended.
The polyolefins used in the instant invention include but not limited to polypropylene homopolymer and copolymer, polyethylene homopolymer and copolymer(including low density products to high density products), poly-1-butene homopolymer and copolymer, poly4-methyl-1-pentene homopolymer and copolymer, ethylene-propylene copolymer elastomer, propylene-1-butene copolymer resin or elastomer, and propylene4-methyl-1-pentene copolymer resin or elastomer. Among them, the preferred starting material for the production of modified products is polybutylene.
The polybutylene referred to herein is one butene-1 polymer containing from 80% preferably from 95% and more preferably from 97% by weight of isotactic portions. The weight average molecular weight may range from about 10,000 to about 1,000,000; determined by gel permeation Chromatography. Suitable poly-1-butene also have a density of from 0.875 to 0.925, preferably from 0.900 to 0.920 and most preferably from 0.910 to 0.915. Suitable poly-1-butenes have melt indices in the range of from 0.1 to 5,000, preferably from 0.1 to 200, more preferably from 0.4 to 20, and most preferably from 1.0 to 5 dg/min, as determined by ASTM D-1238 Condition E, at 190xc2x0 C. The intrinsic viscosity of the poly-1-butene may range from 0.07, preferably from 7 at 130xc2x0 C. in xe2x80x9cdecalinxe2x80x9d (decahydronaphthalene).
These poly-1-butene polymers including their methods of preparation, and their properties are known in the art. An exemplary reference containing additional information on polybutylene is U.S. Pat. No. 4,960,820 which is herein incorporated by reference.
A poly-1-butene polymer (PB) usable herein is either a butene-1 homopolymer or a copolymer or a terpolymer. If a butene-1 copolymer is used, the non-butene comonomer content is from 1 to 50 mole %, preferably from 1 to 30 mole % of either ethylene, propylene, or an alpha olefin having from 5 to 8 carbon atoms. The poly-1-butenes can be modified to increase surface activity by reaction with, for example, maleic anhydride.
Suitable poly-1-butenes can be obtained, for example, in accordance with Ziegler-Natta low-pressure polymerization of butene-1, e.g. by polymerizing butene-1 with catalysts of TiCl3 or TiCl3xe2x80x94AlCl3 and Al(C2H5)2Cl at temperatures of 10-100xc2x0 C., preferably 20-40xc2x0 C., e.g. according to the process described in DE-A-1,570,353. It can also be obtained, for example by using TiCl4xe2x80x94MgCl2 catalysts. High melt indices are obtainable by further processing the polymer by peroxide cracking, thermal treatment or irradiation to induce scissions leading to a higher melt flow material.
Duraflex.R. DP0200, a polybutylene polymer produced by Shell Chemical Company, of Houston, Tex. is a particularly suitable polymer. This polymer is a homopolymer with a melt index of 2.0 g/10 min. at 190xc2x0 C. and 2.16 kg and a weight average molecular weight of 439,000.
Further polybutylene polymers and copolymers that are useful in making the new grafted polymers of the present invention are those disclosed in U.S. Pat. Nos. 4,568,713; 5,594,074 and 5,847,051 whose entire contents are incorporated by reference herein.
The graft reaction is preferably carried out in a melt processing reactor such as single or multiple screw extruders, rubber masticators, Banbury processors, Brabender processors, roll-mills and the like.
In carrying out the grafting process of the present invention, the ethylenically unsaturated monomer and peroxide reagents should be mixed with the polyolefin preferably before the polyolefin is heated, and most preferably the ethylenically unsaturated monomer and the peroxide free radical initiator should be mixed prior to adding such mixture to the polyolefin. Although use of a solvent is not required for mixing the reagents with polyolefin, using an inert, low molecular weight, volatile solvent, such as pentane, hexane, or other hydrocarbons, or methylethyl ketone, acetone, or other low molecular weight species, or any other suitable liquid, to coat the polymer with the reagents, can improve the mixing of the reagents and improve the dispersion of the reagent mixture on the polyolefin when so used. The mixture of peroxide initiator and ethylenically unsaturated monomer is added to the polyolefin to coat the polymer with such components of the mixture. If a solvent is used as a coating and dispersion aid for the reagents, after the mixture is coated onto the polyolefin the solvent is evaporated from the polymer, leaving the ethylenically unsaturated monomer and peroxide reagents on the surface of the polyolefin.
The reaction temperature for practicing the invention are typically in the range of 125-250xc2x0 C. Good results are obtained at temperatures of about 180-230xc2x0 C., but preferably 180-220xc2x0 C. The longer the time that the polyolefin is subjected to the reaction temperature, namely the preferred temperature of 180-220xc2x0 C., the greater will be the amount of grafted ethylenically unsaturated monomer, without further degrading the molecular weight of the polyolefin.
In the first preferred embodiment of the invention, the new polymers of the instant invention are made by the method shown in scheme 1. As shown in scheme 1, polybutylene is first grafted (step 1) with maleic anhydride using a free radical initiator such as a peroxide. Subsequent to the maleation step, the grafted polymer is reacted with iminodiacetic acid to give a polymer having two or more functional moieties per grafting site whether one uses one or more moles of iminodiacetic acid. 
Although applicants does not wish to be bound to any theories or mechanisms, it was assumed that iminodiacetic acid prefers to react only with the acid groups of maleated polybutylene, but in fact the reaction is random. The iminodiacteic can also react with active tertiary carbons as shown in scheme 2. Applicants have calculated that in a 5% maleated polybutylene molecule of a million molecular weight unit there could be approximately 300 potentially active carbon atoms per maleic molecule grafted to the polybutylene backbone, thus providing substantially more active carbon for which the iminodiacteic acid can react. It is also possible that maleic anhydride may also be grafted onto the secondary carbon atoms of the polybutylene backbone.
In the second preferred embodiment as shown in scheme 2, the polybutylene is directly grafted with the iminodiacetic acid also using a peroxide free radical initiator. The peroxide generates free radicals that initiate the site for reaction with iminodiacetic acid yielding two acid groups per grafting site. The iminodiacetic acid is grafted onto the tertiary carbon atoms of the polybutylene backbone. It is also possible that the iminodiacetic acid may also be grafted on to the secondary carbon atoms of the polybutylene backbone. 
In the third preferred embodiment shown in scheme 3, an adduct of maleic anhydride and iminodiacetic acid is preformed and then reacted with via peroxide free radical grafting with the polybutylene. It should be noted that the preformed adduct can also be made with the acid or ester instead of the anhydride. The resulting adduct can have carboxamide bonds as well as acid-base adduct bonds depending on whether the adduct is further heated to generate the carboxamide bonds. 
There are certain advantages to adduct formation prior to grafting. The reaction sequence can be discussed as follows: In a two to one mole ration of iminodiacetic to maleic anhydride the first mole of iminodiacetic acid can react to form an amide linkage (carbonyl-nitrogen bond). The second mole reacts with the acid moiety to form an ionic bond with the nitrogen forming the quaternary nitrogen. Under vacuum and heat one can force the reaction to continue by distilling one mole of water per mole of iminodiacetic acid (condensation), thus forming a molecule that has four carboxylic acid groups attached to the maleic anhydride via amide bonds.
Adduct formations shown in scheme IIII can be accompanied by the formation of dimers (see below) and trimers of the adduct. The ratio of monomer to dimer to trimer can be controlled by the reaction conditions (temperature and reaction time), addition of Lupersol 101, as well as use of the salt form of the iminodiacetic acid to form the monomer. 
The adduct dimer is formed by reaction of one of the pendant acid groups of a monomer adduct with the xcex1, xcex2 unsaturated amino functionality of another monomer adduct. This acid catalyzed nucleophilic addition of heteroatoms to an xcex1, xcex2 unsaturated carbonyl group is an example of the Michael addition reaction. This addition reaction is facilitated by the presence of the acid groups, high temperature and long reaction times. However, it should be noted that dimer and trimer adduct formation can be significantly minimized, if desired, by neutralization of the iminodiacetic acid prior to reaction with any base, or by use of the salt (e.g. sodium, potassium salts) of the iminodiacetic acid in the initial adduct formation. This prevents the Michael addition reaction, because the carboxylate anion does not readily add to an xcex1, xcex2 unsaturated carbonyl group.
Next is the compound obtained by following the same reaction sequence as for the dimer but adding up to 2500 ppm of Luppersol 101 before heating the mixture. Trimer formation: 
The method illustrated in scheme 3 is used to further enhance the functionality of the adduct. For example, since the nitrogen atoms of the iminodiacetic is basic it should react with acid groups of the adduct molecule. Therefore, three moles of iminodiacetic acid added to one mole of maleic anhydride can react under heat and vacuum to form five acid groups etc. The resulting structure can look like a dendrite. It is also conceivable that by using an acid catalyst and adjusting the reaction conditions one could form a oligamer greater than (100)n having the basic structural of the dimer or trimer, but still maintain the olefinic group of the maleic anhydride that is needed for the grafting to the polymer backbone. The grafting of a pre-formed adduct containing multiples functional groups of carboxylic acid to the polymer""s backbone would provide means to achieve high levels of polarity to the polybutylene polymer.
The polyfunctional polyolefin compositions of this invention can be bonded to a polar material by heating at least the multifunctional polyolefin composition to melt, and then joining them together, preferably under pressure. For example, when the polar material is not thermoplastic, there can be employed a method which comprises coating or laminating a molten polyfunctional polyolefin composition onto the polar material; a method comprising superimposing both together, and then melt-bonding them under heat; a method comprising adhering the polyfunctional polyolefin composition to the polar material by electrostaticity and then melting the polyfunctional polyolefin composition to laminate it on the polar material; and a method comprising heating the polar material to a temperature above the melting point of the polyfunctional polyolefin composition, and then adhering the polyfunctional polyolefin composition thereto and simultaneously melting it. Where the polar material is thermoplastic, there can be used a method which comprises melting both the polyfunctional polyolefin composition and the polar material and coextruding and laminating them, and a method which comprises coating or laminating the molten polyfunctional polyolefin composition onto the polar material.
Although pre-treatments of one or both surfaces of the adherents, such as a flame treatment, a corona discharge treatment, and/or coating of a primer, are not required in bonding the polyfunctional polyolefin composition of this invention to polar materials, the adherents may be so treated, if desired.
Several batches of polyfunctional polybutylene were made and evaluated to test whether the increased polarity of polybutylene offers a performance advantage as well as diversity in end use application compared to other functionalized or non-functionalized polymers.
When the polyfunctional polyolefin composition of this invention is bonded to polar materials, both initial adhesiveness and durable adhesiveness can be enhanced over the case of using polyfunctional polyolefins graft-modified with unsaturated carboxylic acids or their derivatives. Hence, the laminates or composites obtained can be used for long periods of time under more severe service conditions. The composition of this invention finds many uses such as rustproof coatings or hot melt adhesives for metal tubes or plates, and laminate or composite films and sheets, and containers, tubes and bottles which are useful as packaging materials for foods, liquids, and medicines. The adhesive properties of the polyfunctional polybutylene of the present invention are summarized in Table 1.
The data reported in Table 1 were obtained without any special surface treatment for the aluminum or the stainless steel with the exception of wiping the metal surfaces with isopropanol to remove grease or surface contamination. It is clear that the polybutylene materials which were further modified with iminodiacetic acid, particularly the modified 8340 grade polymer, have substantially better adhesion to steel and aluminum compared to the acrylated grafted polybutylene polymer as well as the non-modified polymer. There is also ample evidence from this data that useful levels of strong adhesion can be achieved with a variety of polar and non-polar polymeric substrates. This coupled with the peel strength data in Table 2 shows the clear advantage, which can be achieved in selected polybutylene materials with the free radical grafting of iminodiacetic acid.
In a fourth preferred embodiment, the functionalized polybutylene of the present invention can be processed under high shear in a mixture of water and a suitable surfactant and can be made into a film forming emulsion. Coating from these emulsions has lower undesirable volatile components than solvent borne coating. The superior functionalized polybutylene is suitable for several new application such as for hot melt adhesives and for emulsions. Applicants have discovered a new method, which extends the state of the art beyond that of maleic anhydride grafting and yields improved functionality in polybutylene. This method results in the grafting of a small molecules of bi-functional n-substituted diacids to a maleic anhydride which can be grafted to polybutylene. The small chelate, iminodiacetic acid (IDA), because it is very reactive and can coordinate with most metals to form stable structures. The increased functionality of the grafted polymer provides higher adhesive strength in adhesive joints in a number of different substrates.
The emulsion are typically made by mixing together at least one grafted polyolefin, water and emulsifying agent to form a mixture. The materials are then stirred under high shear conditions at an effective temperature to achieve proper emulsification.
The emulsions prepared according to the present invention generally contain 25 to 55 weight percent of grafted polyolefin, with a weight percent of grafted polyolefin of 40-55% being the most preferred.
Exemplary of the emulsifying agents, whether used alone or in admixture, are the traditional anionic agents such as the alkali metal salts of fatty acids, alkyl sulfates, alkylsulfonates, alkylarylsulfonates, sulfosuccinates, alkyl phosphates, abietic acid salts, whether or not hydrogenated, nonionic agents such as polyethoxylated fatty alcohols, polyethoxylated and optionally sulfated alkylphenols, polyethoxylated fatty acids, etc. The emulsifying agents are advantageously employed in a proportion of 0.1% to 10% by weight relative to the total weight of the grafted polyolefin. The most preferred amount of surfactant or emulsifying agent is 3 to 8%.
The amount of water in the emulsion generally varies, depending upon the desired concentration, but is generally between 50-80 weight percent, preferably between 55-80 weight percent and most preferably between 60 and 75 weight percent.
Applicants have synthesized emulsions based on the grafted products of the present invention. Two emulsions were prepared, one containing grafted acrylic acid and the other one containing the adduct of maleic anhydride with iminodiacetic acid. The properties of the emulsions are summarized in Table 4.
Glue from emulsions of functionalized PB or PP can be made quite easily. The carboxylic acid groups attached to the polymer""s backbone can react readily with bases such as hexamethyldiamine etc. to cross-link and reduce set-up time.
The grafted polyolefins of the instant invention can be used in the following additional industrial applications:
(1) Thermoset resins wherein a water soluble amine such as hexamethylenediamine reacts with the carboxylic acid portions of the polymer to cross-link under curing conditions.
(2) Hot melt adhesives as shown in Table 1.
(3) The grafted polyolefins can be blended with other polar engineering resins and act as coupling or compatibilizer to improve processability. They can also be blended with polar tackifying resins as well as other nonpolar olefinic polymers as adhesion promoters.
(4) The grafted polyolefins can be used in extrusion processes to prepare tie-layers in multilayer constructions with other polymers, such as PB/tie-layer/polyamide.
(5) The grafted polyolefins of the present invention can also be converted into ionomers by neutralization with bases such as ZnO or Mg(OH)2.